SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f42492448338bf0e0c58a804a0d0f04cb25f59ed23b3cd0cb5d66656f834ef63' 
  AND token = 'hQvQT1fUsDTaBv5DAydQvWV7rFhkcbbVS8cbtryzC84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}